{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,30]],"date-time":"2026-09-30T02:01:38Z","timestamp":1790733698324,"version":"4.1.0"},"reference-count":46,"publisher":"Public Library of Science (PLoS)","issue":"4","license":[{"start":{"date-parts":[[2021,4,22]],"date-time":"2021-04-22T00:00:00Z","timestamp":1619049600000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100000060","name":"National Institute of Allergy and Infectious Diseases","doi-asserted-by":"publisher","award":["HHSN272201700059C"],"award-info":[{"award-number":["HHSN272201700059C"]}],"id":[{"id":"10.13039\/100000060","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100000060","name":"National Institute of Allergy and Infectious Diseases","doi-asserted-by":"publisher","award":["75N93019D00021"],"award-info":[{"award-number":["75N93019D00021"]}],"id":[{"id":"10.13039\/100000060","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100000060","name":"National Institute of Allergy and Infectious Diseases","doi-asserted-by":"publisher","award":["75N93020P00667"],"award-info":[{"award-number":["75N93020P00667"]}],"id":[{"id":"10.13039\/100000060","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Coronavirus CARES Act"},{"DOI":"10.13039\/100006206","name":"Biological and Environmental Research","doi-asserted-by":"publisher","award":["DE-AC05-76RL01830"],"award-info":[{"award-number":["DE-AC05-76RL01830"]}],"id":[{"id":"10.13039\/100006206","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["www.plosone.org"],"crossmark-restriction":false},"short-container-title":["PLoS ONE"],"abstract":"<jats:p>SARS-CoV-2 has caused a global pandemic, and has taken over 1.7 million lives as of mid-December, 2020. Although great progress has been made in the development of effective countermeasures, with several pharmaceutical companies approved or poised to deliver vaccines to market, there is still an unmet need of essential antiviral drugs with therapeutic impact for the treatment of moderate-to-severe COVID-19. Towards this goal, a high-throughput assay was used to screen SARS-CoV-2 nsp15 uracil-dependent endonuclease (endoU) function against 13 thousand compounds from drug and lead repurposing compound libraries. While over 80% of initial hit compounds were pan-assay inhibitory compounds, three hits were confirmed as nsp15 endoU inhibitors in the 1\u201320 \u03bcM range in vitro. Furthermore, Exebryl-1, a \u00df-amyloid anti-aggregation molecule for Alzheimer\u2019s therapy, was shown to have antiviral activity between 10 to 66 \u03bcM, in Vero 76, Caco-2, and Calu-3 cells. Although the inhibitory concentrations determined for Exebryl-1 exceed those recommended for therapeutic intervention, our findings show great promise for further optimization of Exebryl-1 as an nsp15 endoU inhibitor and as a SARS-CoV-2 antiviral.<\/jats:p>","DOI":"10.1371\/journal.pone.0250019","type":"journal-article","created":{"date-parts":[[2021,4,22]],"date-time":"2021-04-22T14:37:16Z","timestamp":1619102236000},"page":"e0250019","update-policy":"https:\/\/doi.org\/10.1371\/journal.pone.corrections_policy","source":"Crossref","is-referenced-by-count":33,"title":["High-throughput screening of the ReFRAME, Pandemic Box, and COVID Box drug repurposing libraries against SARS-CoV-2 nsp15 endoribonuclease to identify small-molecule inhibitors of viral activity"],"prefix":"10.1371","volume":"16","author":[{"given":"Ryan","family":"Choi","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mowei","family":"Zhou","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Roger","family":"Shek","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jesse W.","family":"Wilson","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5431-3489","authenticated-orcid":true,"given":"Logan","family":"Tillery","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Justin K.","family":"Craig","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Indraneel A.","family":"Salukhe","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sarah E.","family":"Hickson","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Neeraj","family":"Kumar","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Rhema M.","family":"James","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3639-1061","authenticated-orcid":true,"given":"Garry W.","family":"Buchko","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ruilian","family":"Wu","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sydney","family":"Huff","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tu-Trinh","family":"Nguyen","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Brett L.","family":"Hurst","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sara","family":"Cherry","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lynn K.","family":"Barrett","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jennifer L.","family":"Hyde","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6141-2015","authenticated-orcid":true,"given":"Wesley C.","family":"Van Voorhis","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"340","published-online":{"date-parts":[[2021,4,22]]},"reference":[{"issue":"7798","key":"pone.0250019.ref001","doi-asserted-by":"crossref","first-page":"265","DOI":"10.1038\/s41586-020-2008-3","article-title":"A new coronavirus associated with human respiratory disease in China","volume":"579","author":"F Wu","year":"2020","journal-title":"Nature"},{"issue":"7816","key":"pone.0250019.ref002","doi-asserted-by":"crossref","first-page":"459","DOI":"10.1038\/s41586-020-2286-9","article-title":"A SARS-CoV-2 protein interaction map reveals targets for drug repurposing","volume":"583","author":"DE Gordon","year":"2020","journal-title":"Nature"},{"issue":"7811","key":"pone.0250019.ref003","doi-asserted-by":"crossref","first-page":"289","DOI":"10.1038\/s41586-020-2223-y","article-title":"Structure of Mpro from SARS-CoV-2 and discovery of its inhibitors","volume":"582","author":"Z Jin","year":"2020","journal-title":"Nature"},{"issue":"5","key":"pone.0250019.ref004","doi-asserted-by":"crossref","first-page":"991","DOI":"10.1016\/S0022-2836(03)00865-9","article-title":"Unique and conserved features of genome and proteome of SARS-coronavirus, an early split-off from the coronavirus group 2 lineage","volume":"331","author":"EJ Snijder","year":"2003","journal-title":"J Mol Biol"},{"issue":"34","key":"pone.0250019.ref005","doi-asserted-by":"crossref","first-page":"12694","DOI":"10.1073\/pnas.0403127101","article-title":"Major genetic marker of nidoviruses encodes a replicative endoribonuclease","volume":"101","author":"KA Ivanov","year":"2004","journal-title":"Proc Natl Acad Sci U S A"},{"key":"pone.0250019.ref006","doi-asserted-by":"crossref","first-page":"157","DOI":"10.1016\/j.virol.2017.12.024","article-title":"An \"Old\" protein with a new story: Coronavirus endoribonuclease is important for evading host antiviral defenses","volume":"517","author":"X Deng","year":"2018","journal-title":"Virology"},{"issue":"14","key":"pone.0250019.ref007","doi-asserted-by":"crossref","first-page":"8094","DOI":"10.1073\/pnas.1921485117","article-title":"Coronavirus endoribonuclease targets viral polyuridine sequences to evade activating host sensors","volume":"117","author":"M Hackbart","year":"2020","journal-title":"Proceedings of the National Academy of Sciences of the United States of America"},{"issue":"21","key":"pone.0250019.ref008","doi-asserted-by":"crossref","first-page":"E4251","DOI":"10.1073\/pnas.1618310114","article-title":"Coronavirus nonstructural protein 15 mediates evasion of dsRNA sensors and limits apoptosis in macrophages","volume":"114","author":"X Deng","year":"2017","journal-title":"Proc Natl Acad Sci U S A"},{"issue":"6","key":"pone.0250019.ref009","doi-asserted-by":"crossref","first-page":"1400","DOI":"10.1093\/cid\/ciaa410","article-title":"Comparative Replication and Immune Activation Profiles of SARS-CoV-2 and SARS-CoV in Human Lungs: An Ex Vivo Study With Implications for the Pathogenesis of COVID-19","volume":"71","author":"H Chu","year":"2020","journal-title":"Clinical Infectious Diseases"},{"issue":"1","key":"pone.0250019.ref010","doi-asserted-by":"crossref","first-page":"108234","DOI":"10.1016\/j.celrep.2020.108234","article-title":"Evasion of Type I Interferon by SARS-CoV-2","volume":"33","author":"H Xia","year":"2020","journal-title":"Cell reports"},{"issue":"33","key":"pone.0250019.ref011","doi-asserted-by":"crossref","first-page":"12365","DOI":"10.1073\/pnas.0602426103","article-title":"The structure of the endoribonuclease XendoU: From small nucleolar RNA processing to severe acute respiratory syndrome coronavirus replication","volume":"103","author":"F Renzi","year":"2006","journal-title":"Proceedings of the National Academy of Sciences"},{"issue":"16","key":"pone.0250019.ref012","doi-asserted-by":"crossref","first-page":"7909","DOI":"10.1128\/JVI.00525-06","article-title":"New antiviral target revealed by the hexameric structure of mouse hepatitis virus nonstructural protein nsp15","volume":"80","author":"X Xu","year":"2006","journal-title":"J Virol"},{"issue":"7","key":"pone.0250019.ref013","doi-asserted-by":"crossref","first-page":"1596","DOI":"10.1002\/pro.3873","article-title":"Crystal structure of Nsp15 endoribonuclease NendoU from SARS-CoV-2","volume":"29","author":"Y Kim","year":"2020","journal-title":"Protein Sci"},{"issue":"22","key":"pone.0250019.ref014","doi-asserted-by":"crossref","DOI":"10.1128\/JVI.00893-18","article-title":"Structural and Biochemical Characterization of Endoribonuclease Nsp15 Encoded by Middle East Respiratory Syndrome Coronavirus","volume":"92","author":"L Zhang","year":"2018","journal-title":"J Virol"},{"key":"pone.0250019.ref015","article-title":"Tipiracil binds to uridine site and inhibits Nsp15 endoribonuclease NendoU from SARS-CoV-2","volume":"2020","author":"Y Kim","journal-title":"bioRxiv"},{"key":"pone.0250019.ref016","article-title":"Betulonic acid derivatives inhibiting coronavirus replication in cell culture via the nsp15 endoribonuclease","volume":"2020","author":"B Krasniqi","journal-title":"bioRxiv"},{"issue":"42","key":"pone.0250019.ref017","doi-asserted-by":"crossref","first-page":"10750","DOI":"10.1073\/pnas.1810137115","article-title":"The ReFRAME library as a comprehensive drug repurposing library and its application to the treatment of cryptosporidiosis","volume":"115","author":"J Janes","year":"2018","journal-title":"Proc Natl Acad Sci U S A"},{"issue":"44","key":"pone.0250019.ref018","doi-asserted-by":"crossref","first-page":"55","DOI":"10.1093\/nass\/44.1.55","article-title":"Analysis of the RNase H activity by fluorescence resonance energy transfer","author":"H Miyashiro","year":"2000","journal-title":"Nucleic Acids Symp Ser"},{"issue":"22","key":"pone.0250019.ref019","doi-asserted-by":"crossref","first-page":"12218","DOI":"10.1128\/JVI.78.22.12218-12224.2004","article-title":"The severe acute respiratory syndrome coronavirus Nsp15 protein is an endoribonuclease that prefers manganese as a cofactor","volume":"78","author":"K Bhardwaj","year":"2004","journal-title":"J Virol"},{"issue":"2","key":"pone.0250019.ref020","doi-asserted-by":"crossref","first-page":"67","DOI":"10.1177\/108705719900400206","article-title":"A Simple Statistical Parameter for Use in Evaluation and Validation of High Throughput Screening Assays","volume":"4","author":"JH Zhang","year":"1999","journal-title":"Journal of biomolecular screening"},{"key":"pone.0250019.ref021","unstructured":"Dahlin JL, Baell J, Walters MA. Assay Interference by Chemical Reactivity. In: Markossian S, Sittampalam GS, Grossman A, Brimacombe K, Arkin M, Auld D, et al., editors. Assay Guidance Manual. Bethesda (MD)2004."},{"issue":"6","key":"pone.0250019.ref022","doi-asserted-by":"crossref","first-page":"1265","DOI":"10.1021\/acsptsci.0c00130","article-title":"Ebselen, Disulfiram, Carmofur, PX-12, Tideglusib, and Shikonin Are Nonspecific Promiscuous SARS-CoV-2 Main Protease Inhibitors","volume":"3","author":"C Ma","year":"2020","journal-title":"ACS Pharmacol Transl Sci"},{"issue":"50","key":"pone.0250019.ref023","doi-asserted-by":"crossref","DOI":"10.1126\/sciadv.abe0751","article-title":"Structure and inhibition of the SARS-CoV-2 main protease reveal strategy for developing dual inhibitors against M(pro) and cathepsin L","volume":"6","author":"MD Sacco","year":"2020","journal-title":"Sci Adv."},{"issue":"52","key":"pone.0250019.ref024","doi-asserted-by":"crossref","first-page":"23544","DOI":"10.1002\/anie.202010316","article-title":"Allosteric Inhibition of the SARS-CoV-2 Main Protease: Insights from Mass Spectrometry Based Assays*","volume":"59","author":"TJ El-Baba","year":"2020","journal-title":"Angew Chem Int Ed Engl"},{"issue":"1","key":"pone.0250019.ref025","doi-asserted-by":"crossref","first-page":"190","DOI":"10.1021\/acs.analchem.8b05071","article-title":"Surface-Induced Dissociation: An Effective Method for Characterization of Protein Quaternary Structure","volume":"91","author":"AQ Stiving","year":"2019","journal-title":"Anal Chem"},{"key":"pone.0250019.ref026","article-title":"Higher-order structural characterisation of native proteins and complexes by top-down mass spectrometry","author":"M Zhou","year":"2020","journal-title":"Chemical Science"},{"issue":"4","key":"pone.0250019.ref027","doi-asserted-by":"crossref","first-page":"950","DOI":"10.1128\/AEM.01790-07","article-title":"Suppressing posttranslational gluconoylation of heterologous proteins by metabolic engineering of Escherichia coli","volume":"74","author":"JC Aon","year":"2008","journal-title":"Appl Environ Microbiol"},{"issue":"13","key":"pone.0250019.ref028","doi-asserted-by":"crossref","first-page":"2214","DOI":"10.1093\/bioinformatics\/btv082","article-title":"Fast, accurate, and reliable molecular docking with QuickVina 2","volume":"31","author":"A Alhossary","year":"2015","journal-title":"Bioinformatics (Oxford, England)"},{"issue":"1","key":"pone.0250019.ref029","doi-asserted-by":"crossref","first-page":"15451","DOI":"10.1038\/s41598-017-15571-7","article-title":"Protein-Ligand Blind Docking Using QuickVina-W With Inter-Process Spatio-Temporal Integration","volume":"7","author":"NM Hassan","year":"2017","journal-title":"Scientific reports"},{"issue":"6","key":"pone.0250019.ref030","doi-asserted-by":"crossref","first-page":"3655","DOI":"10.1074\/jbc.M708375200","article-title":"Structural and functional analyses of the severe acute respiratory syndrome coronavirus endoribonuclease Nsp15","volume":"283","author":"K Bhardwaj","year":"2008","journal-title":"J Biol Chem"},{"issue":"32","key":"pone.0250019.ref031","doi-asserted-by":"crossref","first-page":"11892","DOI":"10.1073\/pnas.0601708103","article-title":"Crystal structure and mechanistic determinants of SARS coronavirus nonstructural protein 15 define an endoribonuclease family","volume":"103","author":"S Ricagno","year":"2006","journal-title":"Proc Natl Acad Sci U S A"},{"issue":"1","key":"pone.0250019.ref032","doi-asserted-by":"crossref","first-page":"123","DOI":"10.1073\/pnas.1219899110","article-title":"Antibacterial drug leads targeting isoprenoid biosynthesis","volume":"110","author":"W Zhu","year":"2013","journal-title":"Proceedings of the National Academy of Sciences"},{"issue":"5","key":"pone.0250019.ref033","doi-asserted-by":"crossref","first-page":"388","DOI":"10.1093\/jnci\/85.5.388","article-title":"Phase II study of taxol, merbarone, and piroxantrone in stage IV non-small-cell lung cancer: The Eastern Cooperative Oncology Group Results","volume":"85","author":"AY Chang","year":"1993","journal-title":"J Natl Cancer Inst"},{"issue":"6","key":"pone.0250019.ref034","doi-asserted-by":"crossref","first-page":"1733","DOI":"10.1002\/1097-0142(19940915)74:6<1733::AID-CNCR2820740615>3.0.CO;2-D","article-title":"Evaluation of piroxantrone in women with metastatic breast cancer and failure on nonanthracycline chemotherapy","volume":"74","author":"JN Ingle","year":"1994","journal-title":"Cancer"},{"key":"pone.0250019.ref035","doi-asserted-by":"crossref","unstructured":"Snow AD, Cummings JA, Luke TP, Rockenstein E, Masliah E, editors. Development of exebryl\u20131: A disease modifying small molecule therapeutic that causes a marked clearance of brain amyloid load and improved memory in transgenic mouse models of Alzheimer\u2019s disease. Alzheimer\u2019s Association 10th International Conference on Alzheimer\u2019s Disease and Related Disorders; 2006 01 July 20062006.","DOI":"10.1016\/j.jalz.2006.05.2060"},{"key":"pone.0250019.ref036","article-title":"Exebryl-1: A novel small molecule currently in human clinical trials as a disease-modifying drug for the treatment of Alzheimer\u2019s disease","volume":"5","author":"A Snow","year":"2009","journal-title":"Alzheimers & Dementia\u2014ALZHEIMERS DEMENT"},{"key":"pone.0250019.ref037","unstructured":"ScienceMission.com. ScienceMission.com; [cited 2020 25 July]. Available from: http:\/\/sciencemission.com\/site\/index.php?page=news&type=view&id=posters%2Fexebryl-1-a-novel."},{"issue":"1","key":"pone.0250019.ref038","doi-asserted-by":"crossref","first-page":"207","DOI":"10.1016\/j.pep.2005.01.016","article-title":"Protein production by auto-induction in high density shaking cultures","volume":"41","author":"FW Studier","year":"2005","journal-title":"Protein Expr Purif"},{"issue":"Pt 9","key":"pone.0250019.ref039","doi-asserted-by":"crossref","first-page":"998","DOI":"10.1107\/S1744309111017374","article-title":"Immobilized metal-affinity chromatography protein-recovery screening is predictive of crystallographic structure success","volume":"67","author":"R Choi","year":"2011","journal-title":"Acta Crystallogr Sect F Struct Biol Cryst Commun"},{"issue":"18","key":"pone.0250019.ref040","doi-asserted-by":"crossref","first-page":"9976","DOI":"10.1021\/acs.analchem.7b02329","article-title":"Effect of DMSO on Protein Structure and Interactions Assessed by Collision-Induced Dissociation and Unfolding","volume":"89","author":"DS Chan","year":"2017","journal-title":"Analytical chemistry"},{"issue":"16","key":"pone.0250019.ref041","doi-asserted-by":"crossref","first-page":"11195","DOI":"10.1021\/acs.analchem.0c01657","article-title":"Simple and Minimally Invasive SID Devices for Native Mass Spectrometry","volume":"92","author":"DT Snyder","year":"2020","journal-title":"Anal Chem"},{"issue":"8","key":"pone.0250019.ref042","doi-asserted-by":"crossref","first-page":"4370","DOI":"10.1021\/acs.analchem.5b00140","article-title":"Bayesian deconvolution of mass and ion mobility spectra: from binary interactions to polydisperse ensembles","volume":"87","author":"MT Marty","year":"2015","journal-title":"Anal Chem"},{"key":"pone.0250019.ref043","doi-asserted-by":"crossref","DOI":"10.1016\/j.ijms.2020.116477","article-title":"Native Mass Spectrometry Reveals the Simultaneous Binding of Lipids and Zinc to Rhodopsin","volume":"460","author":"CE Norris","year":"2021","journal-title":"Int J Mass Spectrom"},{"key":"pone.0250019.ref044","doi-asserted-by":"crossref","first-page":"33","DOI":"10.1186\/1758-2946-3-33","article-title":"Open Babel: An open chemical toolbox","volume":"3","author":"NM O\u2019Boyle","year":"2011","journal-title":"Journal of cheminformatics"},{"issue":"1","key":"pone.0250019.ref045","doi-asserted-by":"crossref","first-page":"32","DOI":"10.1177\/1094342015594519","article-title":"Application Performance Analysis and Efficient Execution on Systems with multi-core CPUs, GPUs and MICs: A Case Study with Microscopy Image Analysis","volume":"31","author":"G Teodoro","year":"2017","journal-title":"The international journal of high performance computing applications"},{"issue":"1","key":"pone.0250019.ref046","doi-asserted-by":"crossref","first-page":"207","DOI":"10.1039\/C5SC02678D","article-title":"Accurate calculation of the absolute free energy of binding for drug molecules","volume":"7","author":"M Aldeghi","year":"2016","journal-title":"Chemical science"}],"container-title":["PLOS ONE"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.pone.0250019","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2021,4,22]],"date-time":"2021-04-22T14:38:16Z","timestamp":1619102296000},"score":1,"resource":{"primary":{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.pone.0250019"}},"subtitle":[],"editor":[{"given":"Alexander","family":"Wlodawer","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"editor"}]}],"short-title":[],"issued":{"date-parts":[[2021,4,22]]},"references-count":46,"journal-issue":{"issue":"4","published-online":{"date-parts":[[2021,4,22]]}},"URL":"https:\/\/doi.org\/10.1371\/journal.pone.0250019","relation":{"has-preprint":[{"id-type":"doi","id":"10.1101\/2021.01.21.427657","asserted-by":"object"}]},"ISSN":["1932-6203"],"issn-type":[{"value":"1932-6203","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,4,22]]}}}